963 resultados para Preservation of embryo


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This study investigated the effect of human-animal interaction (HAI) and the stress response on the quality of embryo production in superovulated Nelore (Bos indicus) cattle, under tropical conditions. Thirty-two females underwent a superovulation protocol for 5 days. Cortisol concentrations were determined in blood plasma collected on days 0, 4, and 5. Artificial insemination was performed on days 4 and 5, and nonsurgical embryo flushing on day 11. Embryo production and viability were determined. Human stimulation, animal behaviors, accidents, and handling time were recorded to assess HAI. Cattle age was negatively correlated with accidents, frequency of aversive behaviors, and negative stimuli by stockperson during transit through corral compartments to receive superovulation treatments. The factor analysis revealed two distinct groups. The first group was called stressed and had higher cortisol concentration than the nonstressed group, 16.0 +/- 2.1 and 12.5 +/- 1.0 ng/mL, respectively. Comparisons between these groups showed that the frequency of voice emissions by the stockperson and the number of accidents were higher in the stressed group, and also, the mean handling time was longer in the stressed group than for the nonstressed. As a result, viability rate of the embryos was 19% lower in the stressed group (P < 0.05). This indicates that intensive negative HAI is likely related to stress, which affects embryo production in a superovulation program.

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In a 2D parameter space, by using nine experimental time series of a Clitia`s circuit, we characterized three codimension-1 chaotic fibers parallel to a period-3 window. To show the local preservation of the properties of the chaotic attractors in each fiber, we applied the closed return technique and two distinct topological methods. With the first topological method we calculated the linking, numbers in the sets of unstable periodic orbits, and with the second one we obtained the symbolic planes and the topological entropies by applying symbolic dynamic analysis. (C) 2007 Elsevier Ltd. All rights reserved.

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This futuristic article discusses the shift in academic and research libraries to electronic collections in the context of information access, costs, publication models, and preservation of content. Certain factors currently complicate the shift to electronic formats and challenge their widespread acceptance. Future scenarios spanning skill ecosystems, technologies and workflows, and societal implications are explored as logical outgrowths of present circumstances.

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From a financial perspective, this dissertation analyzes the Brazilian mutual fund industry performance for an average retail client. The most representative funds for the local population, that are the fixed income open-end ones, will be selected and their performance will be measured aiming to answer if clients of this industry obtained a proper return over their investments in the period between August 2010 and August 2013. A proper return will be understood as the preservation of the purchasing power of the individual´s savings, what is achieved with a positive performance of a mutual fund after discounting taxes, administrative fees and inflation. After obtaining an answer for the previous question, this dissertation will explore a possible alternative solution: Tesouro Direto, that is an example of a financial approach that could foster the disintermediation between savings and investments through electronic channels. New electronic platforms, with a broader scope, could be utilized to increase the efficiency of funding productive investments through better remunerating Brazilian savings. Tesouro Direto may point towards a new paradigm.

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The Portuguese community schools of the United States located in the areas of larger Portuguese population concentration are social organizations that come materializing throughout decades the designs of the educative policies of the Portuguese government in relation to the expansion and preservation of the language, the culture and the history of Portugal. These designs of the educative policies are enrolled in the Constitution of the Republic (1976), in the Basic Law of Educative System (1986) and, over all, in the successive legislative norms (Decree-laws and ordinances) of the successive governments. Portuguese community schools in the United States are structuralized in analogous way to schools of the Portuguese geographic space. For this qualitative study (multiple case), four directors of Portuguese schools of the East Coast of the United States were interviewed; two schools are in the state of Rhode Island and the other two are in the state of Massachusetts. Also, it was administered the questionnaire on practices of leadership “Leadership Practices Inventory” (LPI) of Kouzes and Posner (2002) to collect additional data about practices of leadership on the directors of the schools. The LPI evaluates practices of leadership classifying them in five domains: (a) Model the way; (b) Inspire a shared vision; (c) Challenge the process; (d) Enable others to act; and, (e) Encourage the heart. Results of this qualitative research indicate that the Portuguese Government has not had an educative policy stimulant, coherent and consistent of support, incentive, maintenance and diffusion of the Portuguese language and culture and the directors of the studied schools they have a proactive and serving leadership style in conducting the management of Portuguese community schools. The five practices of leadership are highly practiced by the directors of the studied schools above all the practices “Enable others to act” and “Encourage the heart”.

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A comparison was done between the F. Paulino jejunal pouch (FP) and a jejunal pouch (JP) as esophagusduodenum interpositional graft, for replacing the stomach after total gastrectomy. It was investigated the effect of the two procedures on esophagus histology, nutritional state and serum gastrin in rats. Methods: Male Wistar rats weighing 282±17g were randomly submitted to sham operation (S), FP and JP after total gastrectomy. After eight weeks the rats were killed with overdose of anesthetic and tissue was taken from the distal esophagus for histology. Serum levels of total proteins, albumin, iron, transferring, folate, cobalamine, calcium, as well as serum gastrin were determined. Survival was considered. Results: Fourty six rats were operated and thirty survived for eight weeks. Five (33.3%) died after FP and 11 (52.3%) after JP (p<0.05). Postoperative esophagitis occurred in 6 JP rats. At 8th week, no difference was observed on body weight when compared FP and JP rats (p>0.05). The JP rats had a significant decrease in serum albumin, glucose, transferrin, iron, folate and calcium, compared to sham (p<0.05). Serum gastrin, iron and calcium were significantly higher in JP rats than in FP rats (p<0.05). In FP rats, transferrin and cobalamine showed significant decrease comparing the preoperative with 8th week levels (p<0.05). Conclusion: F. Paulino pouch in rats had lower mortality than JP, and esophagitis was not detected in it. JP rats had serum gastrin, iron and calcium unaffected, possibly because of preservation of duodenal passage

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The venom of Crotalus durissus terrificus snakes presents various substances, including a serine protease with thrombin-like activity, called gyroxin, that clots plasmatic fibrinogen and promote the fibrin formation. The aim of this study was to purify and structurally characterize the gyroxin enzyme from Crotalus durissus terrificus venom. For isolation and purification, the following methods were employed: gel filtration on Sephadex G75 column and affinity chromatography on benzamidine Sepharose 6B; 12% SDS-PAGE under reducing conditions; N-terminal sequence analysis; cDNA cloning and expression through RT-PCR and crystallization tests. Theoretical molecular modeling was performed using bioinformatics tools based on comparative analysis of other serine proteases deposited in the NCBI (National Center for Biotechnology Information) database. Protein N-terminal sequencing produced a single chain with a molecular mass of similar to 30 kDa while its full-length cDNA had 714 bp which encoded a mature protein containing 238 amino acids. Crystals were obtained from the solutions 2 and 5 of the Crystal Screen Kit (R), two and one respectively, that reveal the protein constitution of the sample. For multiple sequence alignments of gyroxin-like B2.1 with six other serine proteases obtained from snake venoms (SVSPs), the preservation of cysteine residues and their main structural elements (alpha-helices, beta-barrel and loops) was indicated. The localization of the catalytic triad in His57, Asp102 and Ser198 as well as S1 and S2 specific activity sites in Thr193 and Gli215 amino acids was pointed. The area of recognition and cleavage of fibrinogen in SVSPs for modeling gyroxin B2.1 sequence was located at Arg60, Arg72, Gln75, Arg81, Arg82, Lis85, Glu86 and Lis87 residues. Theoretical modeling of gyroxin fraction generated a classical structure consisting of two alpha-helices, two beta-barrel structures, five disulfide bridges and loops in positions 37, 60, 70, 99, 148, 174 and 218. These results provided information about the functional structure of gyroxin allowing its application in the design of new drugs.

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The mechanisms controlling the outcome of donor cell-derived mitochondrial DNA (mtDNA) in cloned animals remain largely unknown. This research was designed to investigate the kinetics of somatic and embryonic mtDNA in reconstructed bovine embryos during preimplantation development, as well as in cloned animals. The experiment involved two different procedures of embryo reconstruction and their evaluation at five distinct phases of embryo development to measure the proportion of donor cell mtDNA (Bos indicus), as well as the segregation of this mtDNA during cleavage. The ratio of donor cell (B. indicus) to host oocyte (B. taurus) mtDNA (heteroplasmy) from blastomere- (NT-B) and fibroblast- (NT-F) reconstructed embryos was estimated using an allele-specific PCR with fluorochrome-stained specific primers in each sampled blastomere, in whole blastocysts, and in the tissues of a fibroblast-derived newborn clone. NT-B zygotes and blastocysts show similar levels of heteroplasmy (11.0% and 14.0%, respectively), despite a significant decrease at the 9-16 cell stage (5.8%; p < 0.05). Heteroplasmy levels in NT-F reconstructed zygotes, however, increased from an initial low level (4.7%), to 12.9% (p < 0.05) at the 9-16 cell stage. The NT-F blastocysts contained low levels of heteroplasmy (2.2%) and no somatic-derived mtDNA was detected in the gametes or the tissues of the newborn calf cloned. These results suggest that, in contrast to the mtDNA of blastomeres, that of somatic cells either undergoes replication or escapes degradation during cleavage, although it is degraded later after the blastocyst stage or lost during somatic development, as revealed by the lack of donor cell mtDNA at birth.

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Cryopreservation of ovarian cortex has important implications in the preservation of fertility and biodiversity in animal species. Slow freezing of cat ovarian tissue resulted in the preservation of follicular morphology and in the follicular development after xenografting. Vitrification has been recently applied to ovarian tissues of different species, but no information is available on the effect of this method on feline ovarian cortex. Moreover, meiotic competence of fully grown oocytes isolated from cryopreserved tissue has not been reported. The aim of this study was to evaluate the effect of vitrification of feline ovarian cortex on follicular morphology and oocyte integrity, as well as meiotic competence. A total of 352 fragments (1.52 mm3) were obtained from ovarian cortical tissues: 176 were vitrified and 176 were used fresh as control. Histological evaluation of fresh and vitrified fragments showed intact follicles after cryopreservation procedures with no statistically significant destructive effect from primordial to antral follicles. After IVM, oocytes collected from vitrified ovarian fragment showed a higher proportion of gametes arrested at germinal vesicle (GV) stage compared to those isolated from fresh control tissue (33.8% vs 2.9%; p < 0.001). However, oocytes isolated from vitrified tissues were able to resume meiosis, albeit at lower rate than those collected from fresh tissues (39.8% vs 85.9%; p < 0.00001). Vitrification induced changes in the organization of cytoskeletal elements (actin microfilaments and microtubules) of oocytes, but significantly only for actin network (p < 0.001). Finally, chromatin configuration within the GV was not affected by the cryopreservation procedure. Our study demonstrated that vitrification preserves the integrity of ovarian follicles and that oocytes retrieved from cryopreserved tissue maintain the capability of resuming meiosis. To our knowledge, this has not previously been reported in the cat.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A técnica de agricultura de precisão e a relação solo-paisagem permitem delimitar áreas para o manejo localizado, o que permite a aplicação localizada de insumos agrícolas e, consequentemente, pode contribuir para a preservação de recursos naturais. Portanto, o objetivo deste trabalho foi caracterizar a variabilidade espacial das propriedades químicas e do teor de argila, no contexto da relação solo-paisagem, em um Latossolo sob cultivo de citros. Amostras de solo foram coletadas na profundidade de 0,0-0,2 m, em uma área de 83,5 ha cultivada com citros, na forma de malha, com intervalos regulares de 50 m, com 129 pontos na forma de relevo côncava e 206 pontos na forma plana, totalizando 335 pontos. Os valores obtidos para as variáveis que expressam as propriedades químicas e para o teor de argila do solo foram submetidos à análise estatística descritiva e geoestatística com a modelagem de semivariogramas para a confecção de mapas de krigagem. Os valores de alcance e mapas de krigagem indicaram maiores variabilidades na forma de relevo côncava (segmento topo), quando comparada com a forma plana (segmentos meia encosta e encosta inferior). A identificação de diferentes formas de relevo mostrou-se eficiente no entendimento da variabilidade espacial das propriedades químicas e do teor de argila do solo sob cultivo de citros.

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Isolated iliac artery aneurysms are rare in the general population (0.03%) and represent 2% of all abdominal aneurysms, and the association with Marfan syndrome is even rarer. We report a Marfan syndrome case with an isolated common iliac artery aneurysm treated by using a modified 'stent-graft sandwich' technique, with preservation of the internal iliac artery perfusion. The modified 'stent-graft sandwich' technique involves building an appropriate proximal neck just in the common iliac artery for fittingly housing two new stent-grafts inside, both deployed simultaneously and each one going to both distal iliac arteries (internal and external).

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Purpose: To determine whether the use of ultrasound (US) to guide embryo transfer (ET) in a population previously defined as likely to have easy transfer would change the implantation and pregnancy rates in an ICSI program.Methods: A total of 100 patients identified as likely to have easy transfer after mock transfer were divided into two groups: Group I, US-guided ET (N = 50) and Group II, ET without the aid of US (N = 50).Results: Implantation and pregnancy rates were similar (p = 0.51, p = 0.29) for Group I (19.6%,42%) and Group II (16.3%,30%), as also was the abortion rate (p = 0.55) (Group I: 1/21; Group II: 2/15).Conclusion: As long as previous mock transfers are routinely performed during a cycle preceding assisted reproduction and the clinician considers transfer to be easy, ultrasound does not benefit the process of embryo transfer.

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Purpose: the objective of this study was to determine if the zona thinning (ZT) technique improved the rates of implantation and clinical pregnancy for patients aged, greater than or equal to38 years submitted to an ICSI program.Methods: A total of 100 patients submitted to ICSI and aged, greater than or equal to38 years were divided in a prospective and randomized manner into two groups: Group I - patients submitted to ZT (n = 50); a laser diode with 1.48 mum wavelength (Fertilaser) was used for the ZT procedure with 1-2 irradiations of 10 ms applied to four different positions on the zona pellucida (ZP) of each embryo to thin 60-90% of the ZP (each point with a 15-20 mum length of ZT). Group II - patients with no ZT (n = 50). In both groups, embryo transfer was performed on the second or third day.Results: the age of Group I patients (39.8 +/- 1.3) did not differ (p = 0.67) from that of Group II patients (40 +/- 1.9). The number of oocytes retrieved at metaphase II from Group I (6.4 +/- 4.2) and Group II (6.8 +/- 5) was similar (p = 0.94). Normal fertilization rates and cleavage rates were similar (p = 0.78 and p = 0.63, respectively) for Group I (71.5 +/- 22% and 96.7 +/- 11%) and Group II (73.5 +/- 19.7% and 96 +/- 11%, respectively). The number of embryos transferred was similar (p = 0.53) for the two groups (Group I = 3.1 +/- 1.3; Group II = 2.9 +/- 1.1). The thickness of the ZP of Group I embryos (16.9 +/- 2.4 mum) did not differ (p = 0.97) from that of Group II embryos (16.9 +/- 2.3 mum). The rates of embryo implantation and clinical pregnancy per embryo transfer were similar (p = 0.67, p = 0.61) for Group I (7 and 16%, respectively) and for Group II (8.2 and 22%, respectively).Conclusions: These results suggest that ZT in the population aged, 38 years may have no impact on ICSI success rates. However, this conclusion is limited to a situation in which length of the laser ZT was less than or equal to 20 mum and the laser was applied to four different positions.